Arrangement for producing rectangular alternating currents



Patented Dee 10, 1935 UNITED STATES ARRANGEMENT FOR PRODUCING RECTAN- GULAR ALTERNATING CURRENTS Dietrich Prinz, Berlin, Germany, assignor to Telei'unken Gcsellschaft fiir DrahtloseTelegraphic m. b. IL, Berlin, Germany, a. corporation oi Germany Application February 17, 1933,

Serial No. 657,247

In Germany February 19, 1932 11 Claims.

An object of the present invention is to generate alternating voltages and currents, the curves of which have a rectangular shape.

The invention, which utilizes systems having irregular current voltagecharacteristic, i. e., in which a continuous variation of the applied voltage, or the current passing therethrough, causes a sudden change of the current passed through the system, or the applied voltage respectively, will now be described. In describing the invention reference will be made to the attached drawing, in which:

Figures 1 and 2.serve to illustrate the-principle of the invention;

Figure 3 shows a circuit arranged in accordance with the invention; and I Figure 4 schematically represents the time of pulsations oi the individual glow discharge systems of Figure 3.

In the following description these systems are simply designated as relaxation system and as such they are known in great numbers. Any system having a falling characteristic may become a relaxation system by suitably connecting it, in a known manner, with ohmic resistances,

, such as, for instance, gas filled discharge tubes (glow tube), dynatrcn, magnetron, Habann-tube, high vacuum tube circuits with ohmic back coupling, etc. The high vacuum tube circuits are better suited due to their small inertia, particlelarly when used for high frequencies. However, for the sake of simplicity in the following examples the relaxation system is represented by the glow tube.

A relaxation circuit may be characterized by the fact that it may assume two different states for the same outer condition either one of which depends only upon the preceding condition. Thus, for instance, a glow tube with a potential applied to it, whose value is between itsignition potential and its extinction potential, may either be permeable or impermeable to the current, depending upon whether the potential applied previously was higher than the ignition potential or lower than the extinction potential. An increase beyond the ignition potential, or a decrease below the extinction potential, respectively, during practically any short period,'is suflicient in order to cause the glow tube to skip over from one state into the other state. This sudden transition may be effected by a current impulse, for instance,

which may be impressed upon the relaxation sys-' I According to Figure 1, the voltage V of the source or current I has a tem in any suitable manner.

value between the ignition potential and the eggtinction potential of the glow tube 2. Connected in series therewith is a resistance 3 having a value B. through which a current I, supplied by another voltage source, not shown, may be passed. Hence, the voltage drop BI is added to or sub- 5 tracted from the voltage V in accordance with the direction of the current I. If V+RI is greater than the ignition potential and if V-RI is lower than the extinction potential of the glow tube, then the latter may be ignited by a current impulse of any short period, in one direction, which has the value I and it may be extinguished by a current impulse in the opposite direction. Furthemore, it is known to cause such relaxation circuits to produce oscillations, so-called relaxation oscillations, by connecting them in cincuit with ohmic resistances and capacities or inductances. Such a circuit is shown in Figure 2, wherein numeral l designates a direct current source, 2 is a glow tube, or any other device with go a characteristic exhibiting discontinuity, 3 rep resents an ohmic resistance, and 4 is a condenser. The latter is charged gradually by the voltage i across the resistance 3 until the ignition potential of the glow tube 2 is attained, whereafter it discharges through the glow tube until the extinction potential is reached and then it is charged again, etc. During every discharge a short current impulse passes through the glow tube. so Now, according to the present invention, in order to produce rectangular alternating current curves, two oscillating relaxation circuits, as per Figure 2, are combined with the unstable relaxation circuit shown in Figure l, in such a manner that a current shock of one oscillating circuit causes the unstable system to alternately skip over from its original state into the other possible state,'while a current shock of the other oscillating circuit causes the unstable system to 40 drop back into the original state.

Figure 3 discloses an embodiment of the invention shown by way oi. example.

The section ab oi'the common source 5 influences the oscillating system I (6 'i 8 9) and the section cd acts upon the oscillating system II (10 H l2 l3). Therefore the glow tubes 9 and I3 'glow periodically, so that periodic currents of short duration pass through the coupling resistances 8 and I2.

The voltage drop of the section bd oi the current source 5 has a value between'the ignition and the extinctionpotentlal of the glow tube I 4. By a suitable design of the resistances 8 and I2,

the currents passing through these resistances c5 during the glow period of the tubes and is cause the glowtube' ll to glow or to be extingulshed in accordance with the manner above described.

If now at the time ti the glow tube 9 glows and likewise the glow tube ii at the time t: and the glow tube 9 again at the time #1, then the glow tube ll will be illuminated during the time ii to t: which means that it is being passed by the current and that between t: and ti it will be dark, therefore no current flows during this time. It will thus be seen that the current passed through the glow tube It has the desired rectangularly shaped curve.

In order to secure a periodically repeated operation, the two oscillating relaxation circuits must have an exactly identical frequency. This having a constant frequency, to act'upon the glow discharge tubes 9 and IS in the oscillating relaxation system.

The frequency of the auxiliary voltage may hereby be a multiple of even number of the required relaxation frequency.

In using glow tubes it is sufficient to apply the alternating voltage to an outer metal layer, as shown atl5 and ii of Figure 3.

The length of the single rectangular oscillations, 1. e. the duration of the current flow through the unstable system, glow tube ll,'may be regulated in, a simple manner by a corresponding variation of the phase with which the alternating voltage acts upon the two oscillating circuits, since, by these phases, the periods t1 and t: are determined, during which the current appears in the circuit I and II, respectively, and therefore termittent discharge .lies between that of the the sudden transition and the dropping back of the unstable system takes place. The difference in phase determines the time tz-h during which theunstable system is causedto assume one of the two possible states (current flow through glow tube l4) In Figure 4 these operations are schematically represented.

In the arrangement of Figure 3 the regulation of the phase is indicated by the provision of a connection of the alternating current source I! with the auxiliary electrode I! across an ohmic resistance l8 and with the auxiliary electrode it across a variable condenser I9.

Ha g thus described my invention and the operat cnthereof, what I claim'is:

1. An oscillation generator circuit comprising three glow discharge devices serially connected together, means for producing an intermittent discharge in one of the outer located glowdischarge devices, and means for producing an in-. in the other outer located device whose time of' occurrence discharges of said first outer located device, means in circuit with one of said two outer devices for causing said third glow device to strike, and in circuit with the other glow discharge of said outer devices for causing the cessation of the glow in said third device.

2. An oscillation generator circuit comprising three glow discharge devices connected in series, individual condensers connected in parallel across the two outer glow devices, a circuit including a sourceof unidirectional potential for charging said condensers and causing same to discharge across said devices to produceinte'rmittent discharges the frequency of which is determined part at least by the rate of charge of the condensers which on reaching a certain voltage limit discharge themselves through their associated glow devices, means for causing the time of occurrence of the discharges of the two condensers 5 through their respective devices to be different and said third glow device to be responsive to the functioning of both of said outer glow devices. i

3. An oscillation generator circuit comprising three glo'w discharge-devices connected in series, individual condensers connected in parallel across the two outer glow devices, a circuit including a source of unidirectional potential for charging said condensers and causing same to discharge 15 I across said devices to produce intermittent discharges the frequency of which is determined in part at least by the rate of charge of the condensers which on reaching a certain voltage limit discharge themselves through their associated 20 glow devices, means for causing the time of occurrence of the discharges of the two condensers through their respective devices to be different and said third glow device to be responsive to the functioning of both of said outer glow devices, and a source of osciilations'in circuit with both of said outer glow devices for stabilizing the frequency of the intermittent discharges produced. I

4. An. oscillation generator circuit comprising of occurrence of the discharges of thetwo condensers through their respective devices to be diflerent and said third glow device to be responsive to the functioning of one of said outer glow 45 devices to glow and to the functioning of thev other of said outer glow devices to cease glowing.

5. An oscillation generator circuit comprising three glow discharge devices connected in series, individual condensers connected in parallel across the two outer glow devices, a circuit including a source of unidirectional potential for charging said condensers and causing same to discharge across said devices to produce intermittent dispart at least by the rate of charge of the condensers which on reaching a certain voltage limit discharge themselves through their associated glow devices, means for causing the time of occurrence of the discharges of the two condensers go through their respective devices to be different and said third glow device to be responsive to the functioning of one ofsaid outer glow devices to glow and to the functioning ofthe other of said outer glow devices to cease glowing, and a of unidirectional potential for charg g said 75 charges the frequency of which is determined in said devices to produce intermittent discharges whose times of occurrence across the respective devices are diflerent and the frequency of which is determined in part at least by the rate of charge of the condensers which on reaching a certain voltage limit discharge th lves through their associated glow devices, means for causing said third glow device to be responsive to the functioning of both said outer glow devices, a source of oscillations for stabilizing Y the frequency of the intermittent discharges of said outer glow devices, individual auxiliary electrodes for each of said outer glow devices, a condenser connected in series with both of the auxiliary electrodes 01' both of said outer glow devices,- a resistance connected to one plate of said last condenser, said source of oscillations being effectively connected in series with said resistance and last condenser.

'7. A system as defined in claim 6, characterized in this, that said auxiliary electrodes are external of their associated 'glow device envelopes and said last condenser is variable.

, circuit including a source of unidirectional potential for charging said condensers and causing same to discharge across said devices to produce intermittent discharges whose times of occurrence across the respective devices are diflferent and the irequencypf which is determined in part at least by the rate of charge of the condensers which on reaching a certain voltage linilt discharge themselves through their associated glow devices, means for causing said third glow device to be responsive to the initiation oi. the discharge in one of the outer glow devices to glow and responsive'to the commencement of the discharge in the other glow device to cease glowing, the time interval between the occurrence of the 5 discharges oi the two outer devices being the duration of the discharge in the third glow device. Y

9. A relaxationosciliation generator comprising two circuit arrangements both of which generate periodically occurring impulses of the same frequency which do not occur simultaneously, and a third circuit arrangement for. generating impulses coupled to said first two circuit arrangements and responsive to one of said two circuit arrangements for initiating an impulse and to the other for stopping said impulse.

10. A relaxation oscillation circuit having, in combination, two generating systems, both 01 which generate periodically. occurring impulses of the same frequency whose times of occurrence are different and a utilization circuit having two conditions of equilibrium coupled to-said two systems and responsive to an impulse from one of said systems for eilecting one condition of equilibrium and responsive to an impulse from the other of said generating systems for efl'ecting the other condition of equilibrium.

11. The method of generating waves which comprises generating oscillations of one Ire-60 quency, generating other oscillations of the same frequency, but whose times of occurrence are difierent from those of the first oscillations and controlling the inception of the generation or still further waves from said first generated oscillations and the completion of said waves from said other generated owillations. DIETRICH PRINZ. 

